Drum rotating device and laundry care apparatus including same

Abstract

A drum rotating device of a laundry care apparatus includes a drum shaft coupled to a drum and a motor including a stator and a rotor that rotates relative to the stator. A gear assembly transmits rotational force of the rotor to the drum shaft. A clutch is connected to the gear assembly and is selectively coupled to the rotor to be rotated together therewith. An actuator is connected to the clutch. The actuator includes drive gears that move the clutch rectilinearly in an axial direction of the drum shaft. The clutch and the rotor include a clutch gear and a coupling gear, respectively, which protrude to face each other in the axial direction and are coupled to each other.

What is claimed is: 
     
         1 . A drum rotating device comprising:
 a drum shaft coupled to a drum;   a motor comprising a stator and a rotor that rotates relative to the stator;   a gear assembly that transmits rotational force of the rotor to the drum shaft;   a clutch that is connected to the gear assembly and is selectively coupled to the rotor to be rotated together with the rotor; and   an actuator that is connected to the clutch and comprises drive gears that move the clutch rectilinearly in an axial direction of the drum shaft,   wherein the clutch and the rotor are provided with a clutch gear and a coupling gear, respectively, which protrude to face each other in the axial direction and are coupled to each other,   wherein the clutch gear has a clutch inclined surface having an axial height increasing gradually along a rotational direction of the rotor, and   wherein the coupling gear has a coupling inclined surface corresponding to the clutch inclined surface and having an axial height decreasing gradually along the rotational direction of the rotor.   
     
     
         2 . The drum rotating device of  claim 1 , wherein the clutch gear comprises:
 the clutch inclined surface having a protruding height increasing gradually toward the rotor along a circumferential direction of the clutch; and   a clutch holding surface connected to the clutch inclined surface and having a steeper inclination angle than the clutch inclined surface.   
     
     
         3 . The drum rotating device of  claim 2 , wherein the rotor is provided with a coupling unit coupled to the clutch,
 wherein the coupling gear is provided on a surface of the coupling unit facing the clutch, and   wherein the coupling gear comprises:
 the coupling inclined surface in contact with the clutch inclined surface and having a protruding height decreasing gradually toward the clutch gear along a circumferential direction of the coupling unit; and 
 a coupling holding surface connected to the coupling inclined surface and having a steeper inclination angle than the coupling inclined surface. 
   
     
     
         4 . The drum rotating device of  claim 1 , wherein the drive gears comprise:
 a pinion part rotated by a drive motor of the actuator; and   a rack part that is linked to the pinion part and moves rectilinearly in the axial direction, and   wherein the clutch is coupled to the rack part and moves rectilinearly in the axial direction.   
     
     
         5 . The drum rotating device of  claim 1 , wherein the drive gears comprise:
 a ball screw rotated by a drive motor of the actuator; and   a ball nut that surrounds the ball screw and moves rectilinearly along the ball screw, and   wherein the clutch is coupled to the ball nut and moves rectilinearly in the axial direction.   
     
     
         6 . The drum rotating device of  claim 1 , wherein a supporter is disposed at a position spaced apart from the rotor along the axial direction, and
 wherein the clutch comprises:
 a locked state in which the clutch is connected to the supporter and the rotation of the clutch stops; 
 a rotating state in which the clutch is coupled to the rotor and rotates together with the rotor; and 
 a neutral state in which the clutch is spaced apart from the supporter and the rotor. 
   
     
     
         7 . The drum rotating device of  claim 6 , wherein when locking protrusions of the clutch are engaged with locking parts of the supporter, the locked state is implemented, and
 when the clutch gear is engaged with the coupling gear, the rotating state is implemented.   
     
     
         8 . The drum rotating device of  claim 6 , wherein the gear assembly comprises:
 a sun gear connected to the rotor;   a carrier that is connected to the drum shaft and rotates together with the drum shaft;   a ring gear that surrounds the sun gear and is engaged with the clutch to rotate together with the clutch; and   a plurality of pinion gears that is engaged with each of the sun gear and the ring gear and is rotatably supported by the carrier, and   wherein an outer circumferential surface of the ring gear and an inner circumferential surface of the clutch are provided with guide teeth and sliding teeth, respectively, which are engaged with each other, so that the clutch and the ring gear rotate together or are locked together.   
     
     
         9 . The drum rotating device of  claim 6 , wherein the clutch transitions from the locked state to the rotating state through the neutral state, and
 wherein, in the neutral state, a synchronization mode in which a rotational speed of the clutch is synchronized with a rotational speed of the rotor is implemented,   wherein the synchronization mode comprises:
 a first synchronization mode in which the rotor rotates without shifting, and the clutch is moved by the actuator to transition from the locked state to the neutral state; and 
 a second synchronization mode in which the rotor is decelerated and the clutch is accelerated by the deceleration of the rotor. 
   
     
     
         10 . The drum rotating device of  claim 9 , wherein when the rotational speeds of the clutch and the rotor are synchronized through the second synchronization mode, the clutch moves toward the rotor and is coupled to a coupling unit of the rotor. 
     
     
         11 . The drum rotating device of  claim 1 , wherein the actuator comprises:
 a drive module having a drive motor and the drive gears driven by the drive motor; and   a clutch lever that is moved rectilinearly by the drive gears and is coupled to the clutch.   
     
     
         12 . The drum rotating device of  claim 11 , wherein the clutch lever surrounds a surface of the clutch. 
     
     
         13 . The drum rotating device of  claim 11 , wherein the clutch lever comprises:
 a lever arm coupled to the clutch; and   a lever gear part connected to the lever arm and extending in the axial direction.   
     
     
         14 . The drum rotating device of  claim 1 , wherein the actuator moves a clutch lever coupled to the clutch, and
 wherein the actuator includes a plurality of sensors spaced apart from each other along a moving direction of the clutch lever, and   wherein the plurality of sensors are configured to detect a displacement of the clutch lever.   
     
     
         15 . The drum rotating device of  claim 1 , wherein the actuator comprises:
 a drive module; and   a clutch lever that is operated by the drive module and moves the clutch along the axial direction, and   wherein the drive module is disposed radially outward of the rotor.   
     
     
         16 . The drum rotating device of  claim 1 , wherein the gear assembly comprises:
 a sun gear connected to the rotor;   a carrier that is connected to the drum shaft and rotates together with the drum shaft;   a ring gear that surrounds the sun gear and is engaged with the clutch to rotate together with the clutch; and   a plurality of pinion gears that is engaged with each of the sun gear and the ring gear and is rotatably supported by the carrier,   wherein the clutch moves rectilinearly along a surface of the ring gear, and   wherein the clutch rotates or stops together with the ring gear.   
     
     
         17 . The drum rotating device of  claim 16 , wherein the surface of the ring gear is provided with guide teeth, and
 wherein an inner circumferential surface of the clutch is provided with sliding teeth that are engaged with the guide teeth and slide along the guide teeth.   
     
     
         18 . The drum rotating device of  claim 1 , wherein a drive shaft of the actuator that rotates the drive gears extends in a direction orthogonal to the drum shaft. 
     
     
         19 . The drum rotating device of  claim 1 , wherein a coupling unit is disposed at a center of the rotor,
 wherein the coupling unit is provided with the coupling gear.   
     
     
         20 . The drum rotating device of  claim 1 , wherein a coupling unit comprises:
 a clutch coupling part having the coupling gear; and   a sun gear coupling part that is arranged concentrically with the clutch coupling part and is coupled to a sun gear of the gear assembly.   
     
     
         21 . The drum rotating device of  claim 1 , wherein a side profile of the clutch gear and a side profile of the coupling gear are asymmetric triangles corresponding to each other. 
     
     
         22 . A laundry care apparatus comprising:
 the drum rotating device of  claim 1 ; and   the drum that is rotated by the drum rotating device and has a storage space formed therein.   
     
     
         23 . A drum rotating device comprising:
 a drum shaft coupled to a drum;   a motor comprising a stator and a rotor that rotates relative to the stator;   a gear assembly that transmits rotational force of the rotor to the drum shaft;   a clutch that is connected to the gear assembly and is selectively coupled to the rotor to be rotated together with the rotor; and   an actuator connected to the clutch and coupling the clutch to the rotor,   wherein the clutch and the rotor are provided with a clutch gear and a coupling gear, respectively, which protrude to face each other in an axial direction of the drum shaft and are coupled to each other,   wherein each of the clutch gear and the coupling gear is asymmetrical left and right relative to a top land thereof, and   wherein the actuator is provided with drive gears that convert rotational movement of a drive motor into rectilinear movement and move the clutch rectilinearly in the axial direction.